Expendable impact energy absorption device for aerial delivery



Ap 1954 M. E. MCCORMACK EXPENDABLE IMPACT ENERGY ABSORPTION DEVICE FOR AERIAL DELIVERY 2 Sheets-Sheet 1 Filed June 28 INVENTOR Mark 5. McCormaclfi BY ATTORNEY April 1964 M. E. MCCORMACK EXPENDABLE IMPACT ENERGY ABSORPTION DEVICE FOR AERIAL DELIVERY 2 Sheets-Sheet 2 Filed June 28, 1962 INVENTOR [Han i 15. MC Cormack ATTORNEY United States Patent 3,130,890 EXPENDABLE MPACT ENERGY ABSORPTIGN DEVICE FOR AERIAL DELIVERY Mark E. McCormack, 26 Leonard Drive, Southboro, Mass. Filed June 28, 1962, Ser. No. 206,105 4 Claims. (Cl. 229-14) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to an Expendable Impact Absorption Device for Aerial Delivery and/or Other Purposes. Whereas, the invention was evolved for use primarily in connection with military operations, it is also well adapted for use in many other airdrop operations of a non-military nature, as well as for various other purposes.

One of the objects of the present invention is to provide an improved device as aforesaid which is so designed and constructed that it can be adapted for use in diversified fields including that of aerial delivery.

Another and important object of the invention is to provide an improved device of the foregoing character in which the resisting load will be taken up in a delayed type action, thus preventing direct shock destruction; it being another object of the invention to provide an inexpensive and expendable impact absorption device in which the cylindrical units or elements are formed and proportioned as to Wall thickness so as to absorb energy in an increasing amount toward that portion of the units where the wall thickness is greatest.

A further object of the invention is to provide a device as aforesaid including rolled units or cylinders of flexible material such as paper, plastic, or the like, means for maintaining said units in rolled condition, and a container for receiving and supporting a plurality of the units in lengthwise stacked or parallel-grouped relationship.

The above and other objects and advantages of the invention will appear from the following description and appended claims when considered in conjunction with the accompanying drawing forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In said drawing:

FIGURE 1 is a perspective view of a rectangular sheet or piece of flexible material such, for example, as paper, having, as shown, a marginal band of adhesive applied to one surface thereof, being shown flat prior to its being diagonally rolled or formed into a tubular form;

FIGURE 2 is a similar view but illustrating an early stage or step of the diagonal rolling operation;

FIGURE 3 is an enlarged elevational view of the sheet of FIGURES 1 and 2, showing the same in tubular form after completion of the diagonal rolling operation;

FIGURE 4 is a vertical sectional view, on a further enlarged scale, of the diagonally rolled tubular unit of FIGURE 3 and showing more clearly the variable wall thickness, as well as the varying outside diameter of the rolled tube, the major wall thickness and also the greater outside diameter of said tube being substantially midway between the ends thereof and decreasing in wall thickness and in tube outside diameter outwardly in opposite directions from said midway point;

FIGURE 4a is a horizontal section taken substantially along the line 4a4a of FIGURE 4, at approximately its greatest diameter;

FIGURE 5 is a somewhat enlarged scale perspective view of one of the assembled expendable impact absorp- 3,130,890 Patented Apr. 28, 1964 tion devices embodying the present invention and showing a plurality of diagonally rolled tube-like units stuffed into a generally cylindrical or tubular container or casing;

FIGURE 6 is a view similar to FIGURE 1 of a modified form of rectangular sheet and having a marginally arranged strip or band of adhesive material on a surface thereof.

FIGURE 7 is an enlarged fragmentary vertical section taken on line 77 of FIGURE 6, looking in the direction of the arrows;

FIGURE 8 is another modified form of rectangular sheet, which may be light metal, for use in producing a diagonally rolled tube-like unit, having formed therein, as shown, a pair of crossed raised reinforcing ribs treated with a coating or spotting of an adhesive, or friction producing compound, such as latex;

FIGURE 9 is an enlarged fragmentary vertical section taken substantially along the line 99 of FIGURE 8, looking in the direction of the arrows;

FIGURE 10 is a perspective view of a further modified form of rectangular sheet or piece of material, formed from metal, or the like, and having perforations, or openings therein; and

FIGURE 11 is an enlarged fragmentary vertical sectional view taken substantially along the line 1111 of FIGURE 10, looking in the direction of the arrows.

Before explaining in detail the present invention, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. It is to be understood also that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring now to the drawing and particularly to FIG- URES 1, 2, 3, 4, 4a and 5 thereof, there is shown one embodiment of the present invention in which, as shown, a rectangular sheet or piece of paper, plastic, or the like 15 having, as shown, a marginal band or strip 16 of adhesive, or some suitable friction-producing compound such, for example, as latex, applied thereto on a face thereof, which is effective to prevent sliding of the internal surfaces of the sheet after being rolled into, as well as while being rolled into, the tubular form indicated as a whole at 17 in FIGURES 3, 4, 4a and 5.

In accordance with the invention, a plurality of these tubes or cylinders 17 is adapted to be stacked or stuffed lengthwise into a container or shell 18 (see FIGURE 5) which container or sleeve is formed from some suitable flexible material, such as pl'astic, paper, cardboard, or metal, being shown, merely for purposes of illustration, as of cylindrical form. The cross-sectional shape of the container 18 may, of course, be varied, as desired.

It is to be noted, see particularly FIGURE 2, that the rectangular sheet 15 is rolled diagonally from corner to corner to form the cylinder or tubular member 17 which has as clearly seen in FIGURES 3 and 4, a variable wall thickness relative to its length. This wall thickness is greatest at approximately a midway point M between the ends of tube 17 and diminishes in thickness in opposite directions outwardly toward said ends E of the tube.

Whereas in FIGURES 1 and 2 the adhesive or frictionproducing compound is shown as being applied as a more or less continuous marginal, or near-marginal strip 16, it can, of course, be applied in the form of a broken line or strip or as spaced dots, spots, or dabs of the substance. No firm amount, design, or arrangement of the adhesive is required, it being merely necessary to apply it in sufficient quantity and in enough areas of the unrolled sheet to serve the desired purpose of preventing sliding or shifting of the convolutions of the diagonally rolled unit 17. This is, of course, desirable so that the lengthwise stacking of a plurality of the rolled units into a suitable container, such as the container 18 in FIGURE 5, can be accomplished with ease and facility to produce the new and novel expendable impact absorption device of the pres ent invention, one illustrative embodiment of which may be seen in FIGURE 5. Each of the variable walled cylinders or units 17 will absorb energy in a progressively increasing amount toward its longitudinal center M Where the wall thickness, as well as the transverse outside diameter is greatest. Upon impact with a surface, such as the ground, in an air-drop operation, for example, the resisting load is taken up in a delayed type action which prevents direct shock destruction.

Model containers with tubular units therein and embodying the invention were tested. One model, includ ing a container similar to container or shell 18 and a plurality of the tubular units like those shown at 17 in FIGURE 5, had a length (height) of 8 /2 inches and a diameter of 4 /2 inches. Another model was smaller, measuring 7 /2 inches in length (height) and being only 3 inches in diameter. In the test of the model, for example, which had an over-all length (height) of 8 /2 inches initially, said model acted exactly as predicted, showing a gradual energy absorption at the beginning of the application of compressive forces and increasing to a maximum of 360 pounds at the end of said pressure application. Other tests were made with models embodying the features of the invention, the same also being entirely satisfactory.

The present invention may be successfully practiced with sheets or pieces of material of various kinds other than paper or cardboard, such as plastic, metal, or the like, the sheets being friction-surfaced on one face, being diagonally rolled into tubular units and then stufied or stacked endwise into a suitable shell or container to produce modified forms or variations which embody the invention. For example, FIGURES 6 and 7 show a rectangular piece of corrugated cardboard 20 having, as shown, a marginal strip 21 of some suitable adhesive or friction material which functions to hold the sheet in its diagonally rolled condition. Sheet 20, as seen in these figures, is diagonally rolled as illustrated in FIGURES 2, 3 and 4 and then placed in a shell or container of any desired cross-sectional shape in much the same manner as are sheets 15, 16 above described. The variable wall thickness and transverse outside diameter variations correspond to those of the units 17.

FIGURES 8 and 9 illustrate another embodiment of rectangular sheet or piece of material which is to be formed into a tubular unit by a diagonal rolling operation. The sheet 22 may be formed from paper, plastic, or thin gauge metal, such as an aluminum alloy, or the like and, as shown, has two crossed and raised embossed ribs 23 which extend diagonally across a face of the sheet 22 from corner to corner thereof. If desired, these ribs may have a thin coating 23a of some suitable adhesive or frictionproducing compound; or they may be spotted at spaced intervals with dabs of the adhesive (not shown). Thus, as in the preceding forms, when sheet 22 is diagonally rolled there will be no shifting of the convolutions thereof. This will permit its being placed, with other like rolled sheets into a suitable container or shell (not shown) to complete the expendable impact absorption device of this form of the invention.

A further form of the invention is shown in FIGURES and 11. In this modification there is shown a rectangular sheet or single relatively thin and pliable piece 24 of paper, plastic, cardboard or metal, having, as shown, a plurality of relatively small openings or perforations 25 formed therein. A face or surface of sheet 24 is preferably provided with a plurality of dabs, spots, or patches 24a of some suitable adhesive material, such as glue, or the like or with any desirable friction producing compound, any of which will serve the purpose of preventing shifting of the convolutions of the sheet 25 when it is diagonally rolled into a tube-like form generally like the rolled unit 17 of FIGURES 3, 4 and 5. If the sheet 24 is of metal it may be welded, soldered or brazed, as well as adhered by means of adhesives. As in the preceding forms of the invention, the sheet 24, when in diagonally rolled condition, is adapted to be used by insertion with other like rolled tubes or units into a preferably openended container or shell similar to that shown at 18 in FIGURE 5.

It is to be understood that regardless of the variations of the basic sheet employed, or the shape or size of the particular container or shell for receiving and holding the diagonally rolled sheets in a frictionally compact manner, as well as the material from which the sheets are formed, the units created from the sheets present variable walled cylinders each of which absorbs energy in an increasing amount toward the center where the wall thickness is greatest, and wherein upon impact the resisting load is taken up in a delayed type action thus preventing direct shock destruction.

I claim:

1. An expendable impact absorption device for use in aerial delivery, said device comprising a hollow container of flexible sheet material, a plurality of hollow empty cylinders of flexible sheet material, said cylinders being stuffed in said container lengthwise thereof and in contact with one another, said cylinders filling said container, and each cylinder having its largest diameter centrally thereof and diminishing in diameter toward both ends.

2. An expendable impact absorption device for use in aerial delivery, comprising a hollow container formed of flexible sheet material, a plurality of empty hollow cylindrical units, each unit comprising a rectangular sheet of flexible material rolled diagonally from corner to corner to provide a series of convolutions of varying diameter, whereby each unit has its greatest wall thickness midway of its ends and diminishes in wall thickness toward its ends, said units filling said container and being stacked therein vertically thereof in parallel relation to each other.

3. An expendable impact absorption device according to claim 2, there being friction producing means between said convolutions of each unit to resist relative shifting of said convolutions.

4. An expendable impact absorption device for use in aerial delivery, said device comprising a hollow container of flexible sheet material, a plurality of hollow empty cylinders of flexible sheet material, said cylinders being stuffed in said container lengthwise thereof and in contact with one another, said cylinders filling said container, said cylinder including a central point and opposite ends, each cylinder having its maximum wall thickness at said central point and diminishing in wall thickness toward both ends.

References Cited in the file of this patent UNITED STATES PATENTS 234,582 Kacer Nov. 16, 1880 415,134 Yocum Nov. 12, 1889 668,518 Higham Feb. 19, 1901 779,155 Gearing Jan. 3, 1905 1,192,744 Brough July 25, 1916 1,212,793 March Jan. 16, 1917 1,313,898 Kieckhefer Aug. 26, 1919 1,470,200 Snyder Oct. 9, 1923 1,589,694 Hohl June 22, 1926 2,194,904 Jackson Mar. 26, 1940 2,266,547 Goodwin Dec. 16, 1941 3,088,624 Kinghorn May 7, 1963 

2. AN EXPENDABLE IMPACT ABSORPTION DEVICE FOR USE IN AERIAL DELIVERY, COMPRISING A HOLLOW CONTAINER FORMED OF FLEXIBLE SHEET MATERIAL, A PLURALITY OF EMPTY HOLLOW CYLINDRICAL UNITS, EACH UNIT COMPRISING A RECTANGULAR SHEET OF FLEXIBLE MATERIAL ROLLED DIAGONALLY FROM CORNER TO CORNER TO PROVIDE A SERIES OF CONVOLUTIONS OF VARYING DIAMETER, WHEREBY EACH UNIT HAS ITS GREATEST WALL THICKNESS MIDWAY OF ITS ENDS AND DIMINISHES IN WALL THICKNESS TOWARD ITS ENDS, SAID UNITS FILLING SAID CONTAINER AND BEING STACKED THEREIN VERTICALLY THEREOF IN PARALLEL RELATION TO EACH OTHER. 